If yours is rubbing from the inside, wouldn't bringing them in more with wider tires rub even more? Sorry I don't know much about this haha.
With the LT295/70R17 Terra Grapplers you could probably run even a 6" backspacing with a PRG leveling kit and not rub the stock spindle. The smaller the backspacing and or wider the rim, the more they stick out, so when you turn they make a bigger arc, and are more likely to rub the inside rear of the front wheel well, at the pinch weld.
With a -12mm offset, a 9" rim has a 4.5" backspacing and will rub with your setup. Rims would stick out 2" more than stock 18's and 20's.
With a 0" offset, 5" backspacing, they'd stick out 1.5" more than stock and would most likely require the pinch weld mod.
With +12mm offset, they would have the stock 5.5" backspacing, so being an inch wider, would stick out 1" more. My rims also stick out 1" more and I needed the pinch weld mod for a 34" Terra, but a 33.2" Terra probably would have fit, with maybe the front mud guard removal. To avoid trimming, this is the one to get. But even better would be a +18 which would only stick out 3/4" with a 9.
Btw, the 9" rims measure 10" and so a 0mm offset and the centerline has 5" to each side. That's the reason a 9" rim with 0mm offset has a 5" backspacing instead of a 4.5" backspacing.
